Liraglutide Vs Tirzepatide: A Comparison Of Two Popular Weight Loss Treatments

There are so many weight loss medications out there that it can be hard to know which one is best for you. Liraglutide (the active ingredient in Saxenda, Victoza and Compounded* Liraglutide with B12) and tirzepatide (the active ingredient in Mounjaro and Zepbound) are two popular options. 

We’ve created this guide on liraglutide vs. tirzepatide to help you understand the differences and discover which treatment could help you reach your weight loss goals. 

How do liraglutide and tirzepatide work? 

Liraglutide and tirzepatide are both injectable weight loss treatments. Here’s how the medications work.

Liraglutide

Liraglutide is a daily injection used to treat obesity and promote weight loss. It belongs to a class of medications called glucagon-like peptide-1 receptor agonists (GLP-1s). This group includes brand-name medications like Ozempic and Wegovy. 

GLP-1 drugs mimic the natural GLP-1 hormone, which is released in the gut after eating. 

Liraglutide works in a few different ways: 

• It acts on parts of the brain that regulate hunger, reducing your appetite
• It lowers blood sugar after eating and prevents blood sugar spikes, reducing cravings for sugary and high-calorie foods 
• It delays the rate at which food leaves your stomach (gastric emptying), increasing fullness [1]    

Together, these effects make it easier to eat balanced meals, smaller portions and fewer calories, promoting weight loss. 

Tirzepatide 

Tirzepatite is GLP-1 and a glucose-dependent inhibitory polypeptide (GIP) receptor agonist. GIP is another natural hormone made in the gut, and tirzepatide mimics both the GLP-1 and GIP hormones. [2] 

It promotes weight loss in similar ways to liraglutide, by reducing appetite, blood sugar levels, and cravings. It also increases feelings of fullness. The targeting of GIP receptors enhances these effects and provides further benefits, like improving fat metabolism. 

Unlike liraglutide, tirzepatide is a once-a-week injection rather than daily. 

How effective is liraglutide vs tirzepatide?

Liraglutide and tirzepatide are both effective weight loss treatments, but research suggests tirzepatide is the more effective medication.  

In clinical trials, people who took liraglutide for 56 weeks lost an average of 8% of their body weight. They also had better glycemic (blood sugar) control, lower blood pressure and a reduced waist circumference. [3]

Participants followed a reduced-calorie diet and did more physical activity alongside taking liraglutide. 

In comparison, a major study on tirzepatide found people who took the medication for 72 weeks lost an average of 20.9% of their body weight. They also saw improvements in their waist circumference, blood pressure and “bad” cholesterol levels. [4] 

Participants in this study also made diet and exercise changes alongside taking tirzepatide.

Safety and side effects of liraglutide vs tirzepatide 

Like all prescription medications, liraglutide and tirzepatide can cause side effects.

Liraglutide

Common side effects of liraglutide include: 

• Nausea 
• Diarrhea 
• Constipation 
• Vomiting 
• Headache 

You might experience side effects when you first start taking the medication or when your dose increases. In most cases, they’re mild to moderate in severity. [3]

More serious side effects of liraglutide include: 

• Pancreatitis (inflammation of the pancreas) 
• Acute gallbladder disease 
• Renal (kidney) impairment 
• Anaphylactic reactions  

These side effects are rare. For example, 0.3% of people taking Saxenda developed pancreatitis in clinical trials. [1]

Liraglutide isn’t recommended for people with a personal or family history of medullary thyroid carcinoma (a type of thyroid cancer) or a rare condition called Multiple Endocrine Neoplasia syndrome type 2. You also shouldn’t take liraglutide during pregnancy.

Tirzepatide 

Tirzepatide has a similar side effect profile to liraglutide. Some of the common side effects include: 

• Nausea 
• Diarrhea 
• Vomiting 
• Constipation
• Stomach pain 

You’re more likely to experience side effects when you first start taking tirzepatide. In most cases, they tend to improve over time. 

More serious, but rare, side effects of tirzepatide include pancreatitis and acute gallbladder disease. If you experience either of these side effects, seek urgent medical attention by calling 911 or visiting the emergency department. [5] 

Symptoms of acute gallbladder problems may include severe pain underneath your right ribcage that may spread to your shoulder or back. This may be accompanied by vomiting, a high temperature or a rapid heartbeat. 

Pancreatitis could be indicated by severe, persistent stomach pain. Severe means:

• It’s so intense (around 8 or more out of 10) that you can’t focus on anything else
• It makes it nearly impossible to handle normal daily tasks (like walking, getting dressed, or eating)
• It doesn’t improve with over-the-counter pain relief or rest
• It radiates to your back or underneath your right ribcage or your right shoulder 
• You also have severe vomiting (3 or more times a day, or having blood or something that looks like coffee grounds in vomit)

Additionally, tirzepatide isn’t recommended for people with personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2. You shouldn’t take the medication during pregnancy. 

Let your prescribing healthcare provider know about any medical conditions you have or any medications you’re taking. They can determine if liraglutide or tirzepatide is right for you. 

Eligibility for liraglutide and tirzepatide 

Liraglutide and tirzepatide share the same eligibility criteria. You may be eligible for these medications if you have a body mass index (BMI) of 30 or higher, or a BMI of 27 or higher and at least one weight-related health condition. 

Weight-related health conditions include: 

• Hypertension (high blood pressure) 
• High cholesterol 
• Prediabetes 
• Type 2 diabetes  
• Obstructive sleep apnea 

Cost of liraglutide and tirzepatide 

Liraglutide and tirzepatide differ in cost. The list price of Saxenda (liraglutide) is $1,449.02 every four weeks and the list price of Mounjaro (tirzepatide) is $1,079.77 every four weeks. [6] [7]

Through ZipHealth, you can also get Compounded* Liraglutide with B12, which costs $179 per month.

In some cases, insurance providers cover weight loss medications. You may need a certain BMI or a health condition like type 2 diabetes to be eligible for coverage.

Which one is right for you? 

Our clinicians assess your medical history and weight loss goals to determine whether liraglutide, tirzepatide, or another weight loss treatment is right for you.  

Find out what treatment is suitable for you on our website.

*Compounded drugs are permitted to be prescribed under federal law but are not FDA-approved and do not undergo FDA review for safety, effectiveness, or quality.

References:

[1] Highlights of prescribing information. [Internet]. Available from: https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/206321s007lbl.pdf 

[2] Dutta P, Kumar Y, Babu AT, Giri Ravindran S, Salam A, Rai B, et al. Tirzepatide: A Promising Drug for Type 2 Diabetes and Beyond. Cureus [Internet]. 2023 May 1;15(5):e38379. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10231274/ 

[3] Pi-Sunyer X, Astrup A, Fujioka K, Greenway F, Halpern A, Krempf M, et al. A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management. New England Journal of Medicine [Internet]. 2015 Jul 2;373(1):11–22. Available from: https://www.nejm.org/doi/full/10.1056/NEJMoa1411892 

[4‌] Jastreboff AM, Aronne LJ, Ahmad NN, Wharton S, Connery L, Alves B, et al. Tirzepatide Once Weekly for the Treatment of Obesity. New England Journal of Medicine [Internet]. 2022 Jun 4;387(3). Available from: https://www.nejm.org/doi/full/10.1056/NEJMoa2206038 

[5] Highlights of prescribing information. [Internet]. Available from: https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/215866s000lbl.pdf 

[6] Saxenda® (liraglutide) injection 3mg List Price & Insurance Coverage Explained | NovoCare® [Internet]. www.novocare.com. Available from: https://www.novocare.com/obesity/products/saxenda/explaining-list-price.html 

[7] Mounjaro Cost Information | With or Without Insurance |Mounjaro® (tirzepatide) injection [Internet]. pricinginfo.lilly.com. Available from: https://pricinginfo.lilly.com/mounjaro